This invention relates to a business record, such as a form, label, tag, or the like, in which different selected areas may be color activated. More particularly, the invention relates to a sheet containing on its surface coatings of selected initially colorless color formers and color developers which, when subjected to heat or pressure, combine to form different colored areas on the sheet.
In the design and use of business forms, labels, tags, and the like, it is desirable to present information in an organized fashion so that information may be readily assimilated. For example, forms typically use headings or columns to identify different categories of information. Lines, rules, and screened areas are also used to delineate specific areas of information.
Color has also been used on business forms to delineate or differentiate information. For example, multipart forms, with each part being printed on different colored paper, have been in use for many years. The different color of each part of the form designates to whom that part is to be given or sent. Others have used different colored forms, labels, or tags to designate, for example, different methods of shipment of packages. As with multi-part forms, however, this method of designation requires that the user maintain an inventory of each different colored form, label, or tag.
To better differentiate categories of information, preprinted screened background areas are often printed in selected colors. One known method used for producing different colors is to apply colored inks during the printing process when the forms are being manufactured. However, such a process requires a separate printing station for each color of ink used. In addition, if the techniques of process color are used, different shades or hues of color can only be produced by printing two or more colors in a superimposed relationship onto selected areas of the form.
In the field of product labeling, direct thermal printing has been a well-known means of non-impact printing. Direct thermal printers are capable of forming colored images by the application of heat to a substrate containing heat-reactive chemicals thereon. Typically, a substrate such as paper is coated with a coating of color forming and color developing reactants which, when heated, combine to form a visible color. When such a coated substrate passes under the print head of a thermal printer, selected areas containing the coating are activated by the heated print elements, forming colored images on the surface of the substrate.
Another method of printing colored images is by applying heat at different temperatures or by applying different quantities of thermal energy to a coated substrate. For example, Iiyama et al U.S. Pat. No. 4,665,410 teach a multi-color thermosensitive recording material formed by applying three or more successively overlaid thermosensitive coloring layers to a support material with intervening decolorizing agent containing layers. Each coloring layer yields a different color depending on the quantity of thermal energy applied. However, such coatings must be applied separately. Also, it is believed that separate printing passes are needed to activate selected colors.
It is also possible to achieve colored images from the use of self-contained carbonless coatings which produce colored images upon the application of pressure such as that from an impact printer. Such coatings are well known, and typically contain dispersed color developers and initially colorless leuco dyes contained in solution within microcapsules.
However, these methods do not presently provide a means for achieving different selected colored areas on a form, label, tag or the like by printing in a single pass. Accordingly, there still exists a need in the art for a business form, label, or the like having selected areas which produce selected colored areas when printed in a single pass through a direct thermal printer or an impact printing device.